Chelsea have the world’s football media in a spell.

Their fluid offensive fervour is backed up by a resolute defensive and a midfield marshalled by not one but two of the Premier League most gifted defensive midfield operators. They have settled into a style of play that suits them, and Conte knows exactly what his best team is. All this has fallen into place in the last month and a half and the results since have been remarkable.

In defeating fellow league contenders Tottenham on Saturday, they extended their win streak to 7 games. In conceding, to a wonderstrike from Christian Ericksen, their defence was breached for the first time since September. They have won their last 7 games on a cumulative scoreline of 19-1. And, of course, they are top of the league.

However, as is often the case, such results tell only half the story. Here’s five reasons Chelsea have cause for concern as we head into December;

 1. Impending Injuries

In playing the same starting XI for each of Chelsea’s last 6 games, Conte has done something Chelsea have failed to do in Premier League history. Such consistency speaks of a manager that knows his best XI but also speaks of a lucky spell of fixtures injury free. Such a streak can only be attributed to luck, as can’t last an entire season. Chelsea have looked imperious in a variety of positions, be it Victor Moses at wing-back or Diego Costa up front, but who could replace them should calamity strike?

Having signed him for over €30 million, Michy Batshuayi has received scant game-time and few would be confidant of him deputising for Costa to the level required.

Similarly, Chelsea fans would likely shudder at the thought of Ivanovic fulfilling the duties of a wing-back to anything near the level of Moses. Indeed, his 10 minute cameo on Saturday was enough to illustrate his lack of pace, a failing only heightened at wing-back.

2. European Advantage Set to End

One of the advantages Chelsea have had this season is no European football, allowing them to pour all their resources into the League. However, many of their title rivals may well be set to join them. Tottenham will likely have only Europa league football in future, and it is unclear how seriously they will take that.

Manchester United have just one group stage fixture left and given Mourinho’s attitude to the competition, may see their involvement end shortly afterwards.

In addition, history would dictate that Manchester City, and particularly Arsenal, are unlikely to feature in Europe much longer. Progression from the group stages is well and good, but an exit in the last 16 would not be out of the ordinary for either side.

As such, Chelsea’s lack of European Football advantage is likely to run out soon, and they have amassed just a one point lead at the table’s summit.

3.  3-4-3 Honeymoon Period

Much has been written about Conte’s 3-4-3 formation, and it has clearly baffled coaches the length and breadth of the country. However, as with any formation, it has its weaknesses. It asks an inordinate amount of the wingbacks, who must cover acres of ground to make the system work. They are essentially tasked with covering the full back and much of the right wing duties, which naturally leaves space when they commit forward (and will also likely fatigue the players in question as the league rolls on).

In a league populated by tacticians such as Guardiola,  Pochettino and Klopp, one would expect someone to devise a system to take advantage of such vulnerabilities at some stage.

4. Unhappy Fringe Players?

Chelsea’s settled XI is great news for players in it, less so for those on the sideline. Players the calibre of Willian, Oscar and Fabregas are not used to sustained periods on the bench, and keeping them happy will be a tough assignment for Conte. Indeed, with a transfer window looming, these players would be forgiven for considering a move away from Stamford Bridge in search for first team football.

Bids for such players are already rumoured to be in the offing, and they are likely to be multiplied in coming weeks.

5. David Luiz

The transformation of David Luiz has been incredible since joining Chelsea. He has looked poised and positionally disciplined in a way never before seen in his career. Indeed, almost eerily so. Footballers can learn a huge amount from coaches such as Conte but Luiz’s transformation has the ‘too good to be true’ ring about it.

Against Spurs on Saturday he showed tendencies to launch himself out of position needlessly, on one occasion falling over, ultimately leading to Ericksen’s goal. As the season wears on, such tendencies will continue to resurface, and no formation can protect a team from Luiz when he’s in the mood.

Colm Egan, Pundit Arena